• Design, develop, and maintain backend systems and REST APIs serving web and mobile applications.
• Analyze requirements, propose technical solutions, design service architecture, databases, and processing flows.
• Optimize performance, reliability, and scalability: caching, indexing, connection pooling, message queue.
• Integrate third-party services; implement security, authorization, and session/token management.
• Write technical documents and coding standards; participate in code reviews and process improvements.
• Support operations (CI/CD, logging, monitoring); troubleshoot incidents and optimize infrastructure costs.
• Collaborate closely with Product, Mobile, Frontend, and QA teams to deliver new features.

• 3–5 years of backend development experience (Middle) or 5+ years (Senior); proven experience running production services.
• Proficient in Node.js and at least one additional backend language (Java/Go/.NET/Python); solid understanding of runtime, concurrency, and I/O.
• Solid knowledge of API design: idempotency, versioning, pagination; hands-on experience with popular frameworks (NestJS/Express/Spring Boot/FastAPI…).
• Strong SQL skills (PostgreSQL/MySQL): query optimization, indexing, transactions & isolation; NoSQL (Redis/MongoDB) is a plus.
• Experience with event systems & message queues (Kafka/RabbitMQ/SQS); understanding of event-driven design, saga/outbox, and eventual consistency.
• Good knowledge of security: OAuth2/OIDC, RBAC/ABAC, TLS, input validation; preventing SQLi/XSS/SSRF.
• Basic DevOps skills: Git, CI/CD (Jenkins/GitHub Actions/GitLab), Docker; Kubernetes and cloud experience (AWS/GCP/Azure) preferred.
• Strong analytical, problem-solving, and clean coding skills; writing unit/integration/contract tests and clear documentation.
• English: strong reading comprehension and capable of communicating in technical discussions (meetings, chat, email).

PREFERENCES

• Experience with microservices: service discovery, circuit breaker, retry/backoff; observability (logging/tracing/metrics).
• High-performance architecture: strategic caching, CQRS, partitioning/sharding, read replicas.
• Production operations experience: on-call, RCA/postmortem.
• Contributions to open-source projects, real-world products/services, or cloud certifications.
• Experience with web3 (smart contracts, wallet integration, Web3.js/Ethers.js, on-chain/off-chain transactions) is a plus.